https://jira.opendaylight.org This file is an XML representation of an issue en-us 8.20.10 820010 22-06-2022 https://jira.opendaylight.org/browse/YANGTOOLS-1067 yangtools <p>Most EffectiveStatement subtrees are inlined via grouping/uses mechanics, which we gain control of via <a href="https://jira.opendaylight.org/browse/YANGTOOLS-694" title="Eliminate duplicate DescriptionEffectiveStatementImpl objects" class="issue-link" data-issue-key="YANGTOOLS-694"><del>YANGTOOLS-694</del></a>.</p> <p>Since most effective statements have a SchemaPath, their state depends on it and thus we cannot reasonably share state – this property cascades to parent substatement list – hence we can share very little.</p> <p>Once we get rid of SchemaPath, though, each effective statement's state is (mostly?) dominated by its QName (which dictates substatements' QNames, etc.), hence we can deploy a very efficient flyweight pattern, where we maintain a QNameModule -&gt; template cache and aggressively reuse effective statements.</p> YANGTOOLS-1067

Use flyweight EffectiveStatement implementations

Improvement Medium Resolved Done Robert Varga Robert Varga Sat, 11 Jan 2020 23:11:45 +0000 Sat, 4 Dec 2021 14:11:30 +0000 Sat, 4 Dec 2021 14:11:30 +0000 8.0.0 parser 0 1 <p>Note that CopyHistory and parent's 'isConfiguration' are also contributing to that state (but we should get that at buildEffective() time from <a href="https://jira.opendaylight.org/browse/YANGTOOLS-694" title="Eliminate duplicate DescriptionEffectiveStatementImpl objects" class="issue-link" data-issue-key="YANGTOOLS-694"><del>YANGTOOLS-694</del></a>). The overall matrix of possible states is nevertheless quite small and amenable to caching.</p> <p>The primary goal here is to eliminate duplicate lists (note Object[] is used by RegularImmutableList, too)</p> <p><span class="image-wrap" style=""><img src="https://jira.opendaylight.org/secure/attachment/15911/15911_image-2020-12-03-19-16-01-224.png" height="749" width="1347" style="border: 0px solid black" /></span></p> <p>These typically consist of CopyPolicy.CONTEXT_INDEPENDENT:</p> <p><span class="image-wrap" style=""><img src="https://jira.opendaylight.org/secure/attachment/15912/15912_image-2020-12-03-19-16-57-891.png" height="626" width="1444" style="border: 0px solid black" /></span></p> <p>hence the list should be readily shared</p> <p>Unfortunately the current mode of operation causes a significant CPU regression without any real benefit. This will need to be revisited.</p> <p><span class="image-wrap" style=""><img src="https://jira.opendaylight.org/secure/attachment/16504/16504_junos_yt800_dups.png" height="687" width="1257" style="border: 0px solid black" /></span></p> <p>with SchemaPath out of the picture, the situation is much better, but there is obviously still room for improvement.</p> Blocks YANGTOOLS-694 YANGTOOLS-1066 Relates YANGTOOLS-1209 YANGTOOLS-1212 YANGTOOLS-1213 YANGTOOLS-1214 Development Epic Link YANGTOOLS-652 Rank 0|i03qqn: